Production of thiocarbanilide



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GLAYTUN W. BEDFORD AND ROBERT L. SIYBLE'Y. OF AKRON, OHIO, AhSIGNORS GOODYEAR, TIRE h RUBBER, GOMPANY, OF AKRON, OHIO, A CGHPGR-ATIfil-l re THE onto.

PRODUCTIOLI OF THIGGAEBANILZDE.

Ho Drawing. Griginal application filed August 12, 1918, Seriai No. 249,581. Divided and this applies.

' tiou filtfd,1 ilOV8iYllJCY 2Q, 1919. Eerial 1%. 3 20.253.

T 0 all whom it may concern:

Be it known that We, fmrron W. Bunrono and ROBERT ll. SIBLEY, citizens of the United States, residing at Akron. in the county of Summit and State of Ohio, llllVB invented a new and useful Improvement in the Production of Thiocarbanilide'.of which the following is a specification. The present invention relates to the production of thiocarbanilides by a method peculiarly suitable for use in connection with the vulcanization of caoutchouc.

Thiocarbanilide is Well known to be a valuable commercial accelerator for em pedit-ing and improving thevulcanization of rubber. In the manufacture of thic- -carbanilide from aniline and carbon bisulhide. hydrogen-sulphide is produced in arge quantities and various methods have been resorted to for removing it from the reaction mixture. in order to speed the reaction and to ensure its completion. Sulphur, for example, appears to act as a catalyst and very materially shortens the time of the reaction. Litharge or other metallic oxides may be used which will react with the hydrogen'sulphide to produce metallic sulphides and water. Pyridine may also be used. its basic properties causing it to react with the acidic hydrogen-sulphide.

The present inventors have discovered a means by which the hydrogensulphide may be conveniently and expeditiously removed from the Zone of the reaction, with all of the attendant advantages of this result, by the use of a compound present. in the reaction zone and having a marked afiipity for the hydrogen-sulphide and reacting therewith to produce a substance .'-.Y ich may he permitted to remain admixedwvith the t-liiocarbanilide, where the latter is to be employed as an accelerator in the vulcanization of caoutchouc.

These desirable results are attained by the use of a paranitroso body, such, for example, as para-nitrosophenol, methylaniline.

Example E:

186 gramsaniline (2 molecules).

31% grams carbon bisulphide. Q

150 rams par-unitroso-diinethylaniline (1 molecule).

or paranitrosodi The "proper proportion of carbon hisulphitle is arrived at as follows:

76 grains (1 molecule) for reaction With the aniline.

38 grains molecule) for re cfiion with the base produced by the reaction of hydrogen sulphide with paranitrosodimethyh aniline.

200 grams, excess for solvent action and temperature control.

The paranitioso-diinetliilaniline endearbou bisulphide are mixed, and the aniline is slowly added thereto under a reflux condenser. The liquid is maintained at the boil ing point in order to prevent the accumulation of aniline with a periodic violent reaction.

When the entire quantity of aniline has been added. the heating is continued under a reflux for a few minutes, and the excess carbon bisulphide is then distilled off. The residue which consists of thiocarbanilide in admixture with the thiocarbanilide derivative formed by the reaction of hydrogen sulphide and carbon bisulphide on the paramitroso-dinieth yl-aniline. in the \presence of aniline. may he used Without. further purification tor the vulcanization process. asmall percentage being added to the rubber mi (for' example. from one-half to two per cent). and vulcanization then carried out in the usual manner. v

Example ll: One or three mols of aniline (93 g. or 275} may be used instead of 186 as in Example I. with the result that there will be obtained mixed thiocarba-ni- .lides of slightly different properties. Three H S up to two Inols under the above conditions, final. reaction corresponding to the following equation: (CH3)iNC H}-NO+3C H5IIH5+2CS2 it is evident therefore that when using three mole ofaniline it; IS a better inethool' sulphide present to form a mixture of sym-' metrical and unsymmetrical thio-urea derivatives which we have found to be particularly valuable for the vulcanization 01" caoutchouc.

It will be apparent from the above that in the paranitroso body named We have discovered a substance forming a highly desirable agent for expediting reversible reactions in which hydrogen sulphide is liberated, the affinity of the nitroso body for the hydrogen sulphide being sogreet as to cause the reaction by which it produced in the shortest time to'the highest possible degree of completion. In the examples given a formation o'l 100% of thiooarbanilide is easily attained, and the speed is limited only to the physical conditions of handling the material. It is readily apparent that the reaction may be applied generically to the formation of homologues of thiocarl'ianilide from iiriznary aromatic amines, in general, and it is intended that the terms thiocarbanilide and aniline. as used herein, are to be understood as designating generically theseclasses of compounds respectively The nature of the reaction between paranitroso dimethytaniline and hydrogen sulphide and. o the reaction between this re action proouet and carbon bisulphide, together with the nature and uses of the prodnets are very fully described in-our co-pending applications Serial-No. 249,579 and Serial l 0. 249,580, filed August 12, 1918.

This application is a division of our prior application Serial No. 249,581, filed Augustby way of explanation, except in so far as such limitations form a part of the appended claims, in which it is our intention to claim all novelty inherent in our invention as broadly as is permissibl in view of the prior art. I

What we claim is:

l. The method of producing a substituted thio-urea which consists in carrying out the reaction between a primary aromatic amine and carbon bisulphide in the presence of a paranitroso body.

2. The method of producing a substituted thio-ure-a which consists in carrying out the reaction between aniline and carbon bisulphide in the presence of paranitroso-dimethyl-aniline.

The method of producing a substituted thio-urea which comprises treating at least one mol of aniline with an excess over one mol of carbon bisulphide in the presence of paranitroso-dimethylaniline.

4. The method of producing a substituted thio-urea Which comprises reacting upon aniline with carbon bisulphide in the pres ence of a paranitroso-bo y.

CLAYTON W. BEDFORD. ROBERT T1. SIBLEY. 

